In a typical prior art lipstick dispenser, an elevator cup retains a body of lipstick for axial extension and retraction by a swiveling of a base portion in relation to a body portion of the dispenser. Dispensers have commonly employed a cam member with helical threads formed there along that is rotatably associated with a tubular innerbody. The innerbody is normally formed with opposed longitudinal tracks. The elevator cup typically has opposed lugs that are received through the longitudinal track and associated with the helical threads of the cam member. Under this arrangement, a rotation of the cam member in relation to the tubular innerbody induces the desired axial movement of the elevator cup and the retained body of lipstick as the lugs of the elevator cup slide along the helical threads and the longitudinal tracks.
This basic lipstick dispensing design has demonstrated plural disadvantages that have been well recognized in the cosmetic industry. For example, there can be axial and radial looseness between the various components of the lipstick dispenser that can lead to a perceived lack of quality of the device and, by inference, the retained product. The lipstick product can also be perceived as being inferior when the swivel torque required to operate the dispenser is excessively light or inconsistent. Still further, a loosely retained elevator cup can wobble thereby resulting in damage to the product and again reducing the perceived quality thereof.
Conversely, it has been found that a lipstick mechanism with a smooth feel and with consistent torque characteristics lends a perception of quality to the device with a resultant increase in the perceived value of the product. A frictional drag of sufficient significance imparts a firm feel to the device that gives an impression of luxury. Preferably, the frictional drag will remain generally constant during extension and retraction of the lipstick and without regard to whether the dispenser is substantially full or substantially exhausted of cosmetic.
Prior art inventors have proposed numerous arrangements for meeting these needs and goals. In one construction, flexible tabs have portions that project radially from the innerbody to provide a frictional engagement with the cam or spiral member. That frictional engagement is intended to provide the dispenser with the desired braking effect and constant swivel torque. Other arrangements have produced a similar frictional engagement by the introduction of fins or ribs on the innerbody. It has been found, however, that the tabs and ribs can plastically deform over time thereby losing effectiveness. Additionally, certain of these arrangements can yield an inconsistent swivel torque during travel of the elevator cup since the effective diameter of the relatively moveable components can vary along their length thereby changing the frictional drag in an undesirable manner.
Another problem exhibited by many prior art lipstick dispensers is an unintentional retraction of the elevator cup during use of the dispenser. In such a situation, the force necessary to apply the lipstick tends to drive the elevator cup toward a retracted position as the lugs slip down the helical threads of the cam member. This retraction has been prevented by the provision of a lateral locking track at the distal end of the innerbody longitudinal track. However, when the dispenser is anything other than fully extended, the locking track is inoperative such that inadvertent retraction is not prevented.
Based on the state of the art as summarized above, it becomes clear that there remains a need for an improved cosmetic dispenser that overcomes the difficulties that have been demonstrated by devices of the prior art while providing additional, heretofore unrealized advantages thereover.